What is a Next-Generation Firewall (NGFW)?

A traditional firewall controls access to your network. It checks the traffic that comes in and goes out, making sure it follows the rules you set. This usually involves looking at things like the state, port, and protocol of the traffic. 

However, in today's world, where cyber threats are more sophisticated, you need something more robust. You need a next-generation firewall (NGFW).

One definitive feature of an NGFW is application awareness. It can identify and control applications, even if they try to hide their true identity using evasive tactics. For instance, if an employee is using a risky, unsanctioned app, the NGFW can detect it and block it.

Additionally, NGFWs come with integrated intrusion prevention systems (IPS). Imagine someone trying to pick the lock of your front door. Traditional firewalls might miss this action, but an NGFW with IPS capabilities will detect and stop it immediately. This is particularly useful against advanced threats like zero-day attacks and sophisticated malware. For example, the Cisco NGFW has built-in intrusion prevention that can spot and stop stealthy threats quickly.

But wait, there's more! NGFWs also leverage cloud-delivered threat intelligence. This means they are constantly updated with the latest threat information from global security communities. Picture an NGFW as having a direct line to a global network of detectives who provide real-time updates on the newest criminal methods. Companies like VMware and Cisco integrate this feature, ensuring their NGFWs are always ahead of emerging threats.

In essence, an NGFW is a comprehensive security tool that provides state-of-the-art protection for modern networks. Whether it's blocking risky applications, preventing intrusions, or utilizing real-time threat intelligence, an NGFW offers a multi-faceted approach to network security.

Key differences between traditional firewalls and NGFWs

Traditional firewalls and NGFWs differ significantly in their capabilities and approaches. 

Traffic inspection

Traditional firewalls are like security guards who check IDs at the door. They filter traffic based on predefined rules using packet headers like IP addresses, port numbers, and protocols. This method works for basic traffic but falls short when dealing with modern threats.

On the other hand, NGFWs are more like intelligence agents. They don't just check IDs; they also scan for suspicious behavior and scrutinize the people entering. NGFWs go beyond basic filtering by inspecting the contents of traffic at the application layer. 

For instance, while a traditional firewall might allow HTTP traffic on port 80, an NGFW will analyze whether that traffic is legitimate web browsing or a covert attack.

Integrated security functions

A traditional firewall works similarly to a single-function gadget. In contrast, an NGFW is a multi-tool. It consolidates several security features like Intrusion Prevention Systems (IPS), Secure Sockets Layer (SSL) decryption, and deep packet inspection. 

For example, if someone tried to exploit a known vulnerability, an NGFW with IPS can detect and block the attack in real-time.

Moreover, NGFWs are adept at handling encrypted traffic. Traditional firewalls see encrypted traffic as a black box – they can't peek inside. But NGFWs can decrypt traffic, inspect it for threats, and then re-encrypt it before it reaches its destination. This capability is crucial in today's environment, where a significant portion of web traffic is encrypted with SSL/TLS.

Visibility and control

Traditional firewalls often have a limited view, akin to looking through a peephole. NGFWs give you a panoramic view. They provide detailed insights into network activity, allowing you to see which applications are being used, by whom, and for what purpose. 

For instance, they can distinguish between personal and business use of social media, enabling granular policies that balance security and productivity.

In practice, this means that if an employee is using a file-sharing app, an NGFW can pinpoint this activity and enforce policies specific to that app. Traditional firewalls, however, might only be able to block or allow traffic to certain ports, missing the finer details.

Threat intelligence

This is where NGFWs truly stand out. They often incorporate threat intelligence feeds to stay updated on the latest threats. Traditional firewalls lack this dynamic capability. 

Consider an example where a new type of malware is spreading. An NGFW can quickly adapt to recognize and block this threat, while a traditional firewall might remain oblivious.

So, while both traditional firewalls and NGFWs aim to protect your network, NGFWs do so with far more sophistication and flexibility.

How NGFWs detect and prevent threats

NGFWs use a combination of advanced techniques to keep your company networks safe. One of the primary methods NGFWs use is deep packet inspection (DPI). 

Unlike traditional firewalls that only look at packet headers, NGFWs dig deeper. They inspect the payload of packets to identify malicious content. 

For example, if a packet contains malware disguised as a harmless file, DPI can recognize the threat and block it before it reaches your network.

Further enhancing security, NGFWs leverage threat intelligence feeds. These feeds are continuously updated databases of known threats. So, when a new type of ransomware is identified globally, your NGFW can immediately recognize and block it. 

Say, you get an email with a suspicious attachment. The NGFW, using its threat intelligence, can compare the attachment to known malware signatures and prevent a potential breach.

Another exciting feature is application awareness. NGFWs can identify and control applications regardless of the port, protocol, or IP address used. This means they can detect if someone is trying to use a banned application like a risky file-sharing service. 

For instance, if an employee tries to download an unapproved app, the NGFW can either block the download or limit its functionality to ensure it doesn’t compromise our network.

User identity awareness

NGFWs can integrate with your directory services, like Active Directory, to associate network traffic with specific users. This helps in creating more granular policies. 

If you know that only the marketing team needs access to social media for work purposes, the NGFW can ensure that only their network traffic gets through while blocking others. This kind of specificity prevents misuse and reduces the risk of insider threats.

Behavioral analysis

By monitoring normal network behavior over time, NGFWs can spot anomalies that indicate potential threats. For instance, if a user's device suddenly starts sending large amounts of data to an unknown server, the NGFW can flag this behavior as suspicious and take action.

In essence, NGFWs bring together multiple security functions into one robust tool, providing a comprehensive defense mechanism for your company network. These integrated capabilities ensure that you stay one step ahead of potential threats, keeping your data and systems secure.

What integrated intrusion prevention tools do NGFWs use?

Integrated intrusion prevention systems boost security by identifying and mitigating potential threats before they can cause harm. With this capability, NGFWs ensure that your network security is not just about keeping the bad guys out but also about understanding and controlling what happens within.

For instance, traditional firewalls might block suspicious traffic based on preset rules, but an NGFW with an IPS goes a step further. It can recognize abnormal behaviors in real-time, helping to prevent attacks such as SQL injections or DDoS attacks before they exploit vulnerabilities. This proactive approach defends your network against threats that older firewalls wouldn't even notice.

With a traditional firewall, you have a strong door with a lock. But with a next-gen firewall, you have a smart door that not only locks but also alerts you if someone is trying to pick the lock or if someone behaves strangely once inside. 

For example, if an application suddenly starts sending out a massive amount of data, the IPS can flag this as unusual activity, inspect the traffic, and halt it if necessary.

Moreover, integrating IPS with NGFW simplifies your security infrastructure. Instead of juggling between separate devices for firewall and intrusion prevention, everything is handled in one place. 

This centralization makes it easier to manage and update your security protocols. If a new threat is discovered, your NGFW can quickly be updated to recognize and block it, keeping your network safe without the need for multiple, complex updates across different systems.

Traffic encryption

With the rise of HTTPS, it’s crucial for firewalls to inspect encrypted traffic. NGFWs can decrypt this traffic, inspect it for threats, and then re-encrypt it before it reaches its destination. This ensures that encrypted channels don’t become a blind spot in your security infrastructure.

Antivirus protection

This is another layer of defense that comes integrated with NGFW's IPS. When a new virus strain emerges, the NGFW can update its threat database to include this new strain, ensuring your network is protected against the latest threats. This feature reduces the risk of malware going unnoticed and causing extensive damage.

For example, suppose a new type of ransomware starts spreading. The NGFW's IPS can detect patterns associated with this ransomware and block it before it encrypts your files. Traditional firewalls, however, might not catch this because they don't have the same level of application-awareness or behavior analysis.

Sandboxing

NGFWs use techniques like sandboxing to stop threats in their tracks. Picture a sandbox as a safe space where suspicious files are opened and tested before they're allowed into the main network. 

So, if your NGFW flags a suspicious email attachment, it will send it to the sandbox. It will download and inspect the attachment in this isolated environment. If it discovers it is a ransomware attack, it will neutralize it there before it reaches any sensitive data.

Artificial intelligence

NGFWs analyze patterns and behaviors across the network, learning what normal activity looks like. If something out of the ordinary happens, like a user downloading files at 3 AM, the system takes note. 

This might be flagged as suspicious, triggering further inspection. It's akin to a super-smart security guard who knows the regulars and can spot a newcomer acting strange.

Signature-based detection

This technique involves scanning files for known malware signatures—patterns that are unique to specific malware strains. While it might sound basic, it’s incredibly effective when used alongside more advanced methods. It's like having a cheat sheet of known troublemakers' mugshots.

What does application-level security mean?

A Next-Generation Firewall (NGFW) isn't just your old firewall with a few fancy add-ons. It's a whole new beast that dives deep into the data packets that flow through your network. This means it doesn’t just look at where the data is coming from and where it's going; it also inspects what's inside.

For example, say you've got employees using web applications like Slack or Zoom. Traditional firewalls might only see the traffic going to and from these apps and let it pass through if it’s from a "trusted" source. 

But NGFWs go further. They can peek inside the packets to see if someone's trying to sneak in malware through a chat message in Slack or a file shared on Zoom.

To clarify with another example, a sneaky malware might disguise itself as a PDF file to infiltrate your network. A regular firewall would just see it as harmless traffic. But an NGFW will dissect the contents of the file transfer, find the hidden malware, and block it before it can cause any damage.

Application awareness and control

This is a key feature of NGFWs. Imagine you want to allow employees to use Facebook for marketing purposes but you don't want them spending hours watching videos or playing games. 

An NGFW can distinguish between different types of Facebook traffic. It can let the marketing team post updates while blocking access to games and videos.

In short, Next-Generation Firewalls don't just build a barrier around your network; they actively monitor, analyze, and protect the data that flows through it, all while staying updated on the latest threats.

These techniques combined make NGFWs indispensable tools in the fight against malware. They don't rely on just one method but utilize multiple layers of defense, ensuring that if one technique misses a threat, others are there to pick up the slack.